1. Trigonometry

    Find the exact value of tan(a-b) sin a = 4/5, -3pi/2<a<-pi; tan b = -sqrt2, pi/2<b<pi identity used is: tan(a-b)=(tan a-tan b)/1+tan a tan b simplify answer using radicals. (a is alpha, b is beta)
  2. Tan^2 Integrals

    I'm having a hard time understanding how to do Integrals involving tan^2. I have two problems: 1. Find the integral of (tan^2 y +1)dy 2. Find the integral of (7tan^2 u +15)du 1. My approach to it is to replace the tan^2 y portion of the problem with sec^2
  3. Integration

    Intergrate ¡ì sec^3(x) dx could anybody please check this answer. are the steps correct? thanks. = ¡ì sec x d tan x = sec x tan x - ¡ì tan x d sec x = sec x tan x - ¡ì sec x tan^2(x) dx = sec x tan x + ¡ì sec x dx - ¡ì sec^3(x) dx = sec x tan x
  4. Calc

    intergral of (x^3 -4x + 3)/(2x) dx would this be ln abs(x^3-4x+3) + C? I don't really understand how to solve this problem. d/dx (tan (x^2)) sec^2(x^2)(2x) would this be the correct answer to find the derivative of tan (x^2)? no, because if you
  5. Maths- complex numbers

    Find tan(3 theta) in terms of tan theta Use the formula tan (a + b) = (tan a + tan b)/[1 - tan a tan b) in two steps. First, let a = b = theta and get a formula for tan (2 theta). tan (2 theta) = 2 tan theta/[(1 - tan theta)^2] Then write down the equation
  6. calculus

    Use integration by parts to evaluate the integral of x*sec^2(3x). My answer is ([x*tan(3x)]/3)-[ln(sec(3x))/9] but it's incorrect. u=x dv=sec^2(3x)dx du=dx v=(1/3)tan(3x) [xtan(3x)]/3 - integral of(1/3)tan(3x)dx - (1/3)[ln(sec(3x))/3] - [ln(sec(3x))/9]
  7. Calculus - Integration

    Hello! I really don't think I am understanding my calc hw. Please help me fix my errors. Thank you! 1. integral from 0 to pi/4 of (tanx^2)(secx^4)dx It says u = tan x to substitute So if I use u = tan x, then my du = secx^2 then I have integral of (u^2)
  8. trig

    h t t p : / / i m g 4 0 . i m a g e s h a c k . u s / c o n t e n t . p h p ? p a g e = d o n e& l = i m g 4 0 / 1 4 8 / a s d a s d y e . j p g & v i a = m u p l o a d (def of tan theta = a^-1 o)a = o opposite = adjacent tan theta written with respect to
  9. Math-Trigonometry

    Show that if A, B, and C are the angles of an acute triangle, then tan A + tan B + tan C = tan A tan B tan C. I tried drawing perpendiculars and stuff but it doesn't seem to work? For me, the trig identities don't seem to plug in as well. Help is
  10. integral confusion

    integral of Sec[2x]Tan[2x] i know u is sec 2x du=2sec2xtan2x dx what would i have to multiply with du so it would equal tan 2x dx? if my question is confusing, then here's another example of what i'm talking about: integral of (3x-2)^30 dx u=3x-2 du=3 dx
  11. Calculus

    Calculate the following integral: ∫ sec^4 (3x)/ tan^3 (3x) dx For this one, can I bring up the tan to tan^-3?
  12. Calc

    Hello im trying to integrate tan^3 dx i have solved out the whole thing but it doesnt match up with the solution.. this is what i did: first i broke it up into: integral tan^2x (tanx) dx integral (sec^2x-1)(tanx) dx then i did a u substitution u = secx du
  13. Calc

    Hello im trying to integrate tan^3 dx i have solved out the whole thing but it doesnt match up with the solution.. this is what i did: first i broke it up into: integral tan^2x (tanx) dx integral (sec^2x-1)(tanx) dx then i did a u substitution u = secx du
  14. Calculus Please Check my answer

    find d/dx (integral from 2 to x^4) tan(x^2) dx tan(x^4)^2*4x^3 MY ANSWER
  15. calculus (check my work please)

    Not sure if it is right, I have check with the answer in the book and a few integral calculators but they seem to get a different answer ∫ sec^3(x)tan^3(x) dx ∫ sec^3(x)tan(x)(sec^2(x)-1) dx ∫ tan(x)sec(x)[sec^4(x)-sec^2(x)] dx ∫
  16. Trig - tan 15° using composite argument?

    tan 15° tan (45°-30°) (tan 45° - tan 30°)/1+ tan 45°tan30° (1-√3/3)/(1+1√3/3) then i donnt what to do/ chancel out. Can someone finish it if i didn't get it wrong. thanks in advance
  17. Calculus

    "Evaluate the following indefinite integral using integration by parts: *integral sign* tan^-1(x) dx" I let u = tan^-1(x) and dv = dx. Is that right?
  18. Trigonometry

    Hello, everyone: I am working on finding the exact values of angles that are less common and are therefor not found easily on the Unit Circle (at least, they are not labeled). For example, the problem I am asking about is: 10) Find the exact values of the
  19. Calculus

    Calc length of arc of y=ln(x) from x=1 to x=2 ---- So far: Definite Integral over x=(1,2) of sqrt(1 + 1/x) dx 1/x = tan^2 t x = 1/tan^2 t sqrt(1+1/x) = sqrt(1+tan^2 t) = sec t dx = -2 * tan^-3 t * sec^2 t dt Integrate over x=(1,2): sec^3 t / tan^3 t dt
  20. calculus

    Find the exact value of the given expression. (tan17pi/12 - tan pi/4) / (1+tan 17pi/12 tan pi/4) can you help with this? i got the answer 1/ squareroot 3
  21. calculus

    can anyone tell me if tan-1x= 1 over tan x? No. They are different. tan^-1 (x) is a frequently used way of writing arctan x, which means the angle whose tangent is x. tan (tan^-1 x) = x
  22. Trig.

    sec^2xcotx-cotx=tanx (1/cos)^2 times (1/tan)-(1/tan)=tan (1/cos^2) times (-2/tan)=tan (-2/cos^2tan)times tan=tan(tan) sq. root of (-2/cos^2)= sq. root of (tan^2) sq. root of (2i)/cos=tan I'm not sure if I did this right. If I didn't, can you show me the
  23. Trig

    Can someone check my answers so far? 1. Find the exact value of tan(-3ð) Answer: tan(-3ð) = tan (-3 + 2ð) = tan (-ð) = tan (-ð + 2ð) = tan(ð) = sin (ð)/cos(ð) = (0)/(-1) = 0 Exact value is 0 2. Solve triangleABC is C = 90 degrees, B = 20 degrees,
  24. PreCalculus

    Hi I need some assistance on this problem find the exact value do not use a calculator cot[(-5pi)/12] Here is my attempt RT = square root pi = 3.14...
  25. calculus

    Calculate definite integral of dx/(x^4 * sqrt(x^2 + 3)) Over (1,3) I start with the substitution x = sqrt(3)*tan t so: sqrt(x^2 + 3) = sqrt(3) * sec t dx = sqrt(3) * sec^2 t dt x^4 = 9 * tan^4 t The integral simplifies to: = dt/(tan^3 t * sin t) How do I
  26. Math

    Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value. (tan(π/2)+tan((2π)/3)) / (1-tan(π/2)tan((2π)/3)) Answer=__________ Exact value answer=_________
  27. Calculus 2

    ∫ tan^2 (x) sec^4 (x) dx ∫ [tan^2 (t) + tan^4 (t)] dt ∫ [1-tan^2 (x)] / [sec^2 (x)] dx Trigonometric integral Please show steps so I can understand!
  28. Pre-Cal

    Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. (tan(74°)-tan(14°))/(1+tan(74°)tan(14°)) =__________ Find it's exact value (not decimal form) =__________ Note: A similar question(but with
  29. Maths Calculus Derivatives

    Find the first derivative for the following functions 1) f(x) = sin(cos^2x) cos(sin^3x) 2) f(x) = ( tan 2x - tan x ) / ( 1 + tan x tan 2x ) 3) f(x) = sin { tan ( sqrt x^3 + 6 ) } 4) f(x) = {sec^2(100x) - tan^2(100x)} / x
  30. calculus

    If limit as delta x approaches 0 of tan(0+Δx)-tan(0)/Δx =1 which of the following is false: d/dx [tanx]=1 the slope of y = tan(x) at x = 0 is 1 y = tan(x) is continuous at x = 0 y = tan(x) is differentiable at x = 0
  31. calculus

    Integrate: dx/sqrt(x^2-9) Answer: ln(x + sqrt(x^2 - 9)) + C I'm getting the wrong answer. Where am I going wrong: Substitute: x = 3 * sec t sqrt(x^2 - 9) = sqrt(3) * tan t dx = sqrt(3) * sec t * tan t Integral simplifies to: sec t dt Integrates to: ln|sec
  32. calculus

    I need help on finding the local linear approximation of tan 62 degree. i got 1.77859292096 can someone check if i got it right? tan(60+2) = (tan 60+ tan 2) / (1- tan60 tan 2) But tan2 appx = sin 2deg = sin2PI/180= 2PI/180 tan 62=(tan 60+2PI/180) / (1-
  33. Calculus

    Evaluate the indefinite integral integral sec(t/2) dt= a)ln |sec t +tan t| +C b)ln |sec (t/2) +tan (t/2)| +C c)2tan^2 (t/2)+C d)2ln cos(t/2) +C e)2ln |sec (t/2)+tan (t/2)| +C
  34. Math- Precalculus

    Write the expression as the sine, cosine, tangent of an angle (in radians.) (tan(pi/5)-tan(pi/3))/(1+tan(pi/5)tan(pi/3))
  35. Trig-Weird Geometry Problem

    Determine all triangles ABC for which tan(A-B)+tan(B-C)+tan(C-A)=0. There's a hint: "Can you relate A-B to B-C and C-A?" Should I apply the tangent difference formula (tan(x-y))? Help would be appreciated, thanks.
  36. math 105

    Prove that tan(A+B+C) =(tan A + tan B tan C - tanAtanBtanC) ÷(1-tanAtanB-tanBtanC-tanAtanC)
  37. Calculus

    Evaluate the limit as h -> 0 of: [tan (pi/6 + h) - tan(pi/6)]/h I thought the answer was √3/3, or tan(pi/6, but apparently that is wrong, any tips here?
  38. calculus

    So I am suppose to evaulate this problem y=tan^4(2x) and I am confused. my friend did this : 3 tan ^4 (2x) d sec^ 2x (2x)= 6 tan ^4 (2x) d sec^2 (2x) She says it's right but what confuses me is she deriving the 4 and made it a three? I did the problem like
  39. math

    Write the given expression as the tangent of an angle. tan 7x − tan x/ 1 + tan 7x tan x
  40. Math:)

    Which trigonometric functions are equivalent to tan(theta)? Select all that apply. (2 answers) a. -tan(-theta)**** b. -tan(theta) c. tan(-theta) d. tan(theta+2pi)**** e. tan(theta+pi/2)
  41. Calc

    y= cube root (1+tan(t)) OR y= (1+tan(t))^(1/3) The answer I got was y'= (1/3)(1+tan(t))^(-2/3)*(sec^2(t)) Is this correct?
  42. calculus

    How do I derive the integration reduction formula for tangent? Integral of (tan x)^n dx = ... I can do the derivations for sin/cosine, but I'm getting stuck on tan. Thanks!
  43. Calculus

    What is the integral of 1-tan^2theta from 0 to pi/3? Using the identity tan^2theta=sec^2theta-1, I got my answer to be 2pi/3 - sqrt*3 Can someone verify this for me please?
  44. precalculus

    For each of the following determine whether or not it is an identity and prove your result. a. cos(x)sec(x)-sin^2(x)=cos^2(x) b. tan(x+(pi/4))= (tan(x)+1)/(1-tan(x)) c. (cos(x+y))/(cos(x-y))= (1-tan(x)tan(y))/(1+tan(x)tan(y)) d.
  45. Precalculus/Trig 5

    Find the exact value of thet following trigonometric functions: tan(5pi/6) tan(7pi/6) tan(11pi/6)
  46. trig

    Find the smallest positive value of x(in degree) for which tan(x+100°)=tan(x+50°)*tanx*tan(x-50°)
  47. math (trig)

    Given tan 0 = -5/12 determine the possible values of 0 to the nearest hundreth So what I did is find that tan-1(5/12) equals 0.35. Then because tan can be negative in quadrants 1 and 3 subtract 0.35 from pi and then from 2pi. So I got 2.79 and 5.933 I'm
  48. Clac ii

    integral of tan^5(2x)sec^3/2(2x)dx Y^11/11 - 2/7Y^7 + 1/3Y^3 where: Y = (1 + u^2)^(1/4) and: u = tan(2x)
  49. Pre Cal

    could someone please tell me what the other angle identity of tan is? Thank you much! "...other angle identity of tan x"? in relation to which "other" ? there are many identities dealing with the tangent. The most important is probably tan x = sin x/cos x
  50. Calculus

    I'm having a little trouble with this problem...it would be great if you could point out where I'm going wrong. Hours of Daylight as a Function of Latitude. Let S(x) be the number of sunlight hours on a cloudless June 21st, as a function of latitude, x,
  51. calculus

    find dy/dx y=ln (secx + tanx) Let u= secx + tan x dy/dx= 1/u * du/dx now, put the derivative of d secx/dx + dtanx/dx in. You may have some challenging algebra to simplify it. Use the chain rule. Let y(u) = ln u u(x) = sec x + tan x dy/dx = dy/du*du/dx
  52. Trig

    Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v - u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos v + cos v sin u. cos (v -
  53. Calc 2

    Ok, I have two questions first: 1. I'm asked to find a cartesian equation for the polar graph of this polar equation: r^2 = sin(2(theta)) The answer I got was (x^2+y^2)^2/(2xy) = 2 Is this the correct way to express it? 2. I need to find the cartesian
  54. more trig.... how fun!!!!

    if you can't help me with my first question hopw you can help me with this one. sec(-x)/csc(-x)=tan(x) thanx to anyone who can help From the definition of the sec and csc functions, and the tan function, sec(-x)/csc(-x) = sin(-x)/cos(-x) = tan(-x) However,
  55. Trigonometry desperate help, clueless girl here

    2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) sin(x) + cos(x)=
  56. trig

    Use a sum or difference identity to find the exact value. tan 25deg + tan 5deg / 1-tan 25deg tan 5deg
  57. Calculus

    Find the integral of x/cos^2(x^2)dx The answer is 1/2 tan (x^2) + C. Where does the 1/2 come from?
  58. Trigonometry

    1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin
  59. Math (Double checking trig identity)

    Since sec^2θ - 1 = tan^2θ I know this is trivial, but I want to make sure I'm doing this right before I apply it to the integral I'm trying to solve... If I have some constant a, (a^2secθ)^2 - (a^2)^2 If I wanted to change this to tan would it be:
  60. calculus

    a billboard 20ft tall is located on top of a building with its lower edge 60 ft above the level of a viewers eye. how far from a point directly below the sign should a viewer stand to maximize the angle (theta) between the lines of sight of the top and
  61. Calc BC

    1. Find the indefinite integral. Indefinite integral tan^3(pix/7)sec^2(pix/7)dx 2. Find the indefinite integral by making the substitution x=3tan(theta). Indefinite integral x*sqrt(9+x^2)dx 3. Find the indefinite integral. Indefinite integral
  62. Trig

    Sum and diffence formula Finding Exact value of Tan 105-Tan 10)-15)/1+ tan(105)Tan(-15)
  63. Calc

    Let F(x, y, z) = z tan−1(y^2)i + z^3 ln(x^2 + 10)j + zk. Find the flux of F across S, the part of the paraboloid x^2 + y^2 + z = 19 that lies above the plane z = 3 and is oriented upward. Thanks! STudying for a quiz... *tan−1 is tan^(-1)
  64. mult'vi calc

    Let F(x, y, z) = z tan−1(y^2)i + z^3 ln(x^2 + 10)j + zk. Find the flux of F across S, the part of the paraboloid x^2 + y^2 + z = 19 that lies above the plane z = 3 and is oriented upward. Thanks! STudying for a quiz... *tan−1 is tan^(-1)
  65. tan x = 1/2

    Can someone tell me what the radian value is for this number and how they got it? Thanks On a graph plot the point A(2,1) Let C(2,0) be the point on the x-axis x is the angle AOB and tan x = 1/2 Since angle x is not one of the special angles, you will have
  66. Algebra II

    Find the value of tan[tan^-1 1/2] My answer is 1/2. Is this correct?
  67. Pre-Cal

    1)tan 5 degrees + tan 25 degrees / 1 tan 5 degrees tan 25 degrees = sqrt 3 / 3 Am I correct? 2) Complete the identity tan^2Q - 3sinQtanQsecQ = -2tan^2Q Correct?
  68. Pre-calculus help

    I have two problems I am stuck on, if you could show me how to solve the problems it would be much appreciated. 1) Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 1/6, cos x > 0 sin 2x = cos 2x = tan 2x = 2) Find sin 2x, cos
  69. trig

    please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1- tan 25° tan 5°
  70. trig

    please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1- tan 25° tan 5°
  71. calculus

    Show that tan^3(x)-8(tan^2(x))+17(tan(x)0-8 = 0 has a root in [0.5, 0.6]. Apply the Bisection Method twice to find an interval of length 0.025 containing this root. I have NO idea where to go with that equals 0 part...I could figure it without it but that
  72. Math, Please Help!!!

    How can the right equation be converted into the answer on the left? (sec^4x)(tan^2x)=(tan^2x + tan^4x)sec^2x
  73. Calc

    I have a test soon.. and I really need to know how to do this problem.. please help!!! lim as x-->0 sin^2(x)/tan(x^2) the answer is 1, but I have no clue how to get that! Use series expansions. Look up Taylor expansion on google and study that topic
  74. Math (Trig)

    There's a question on my homework that says: Tan(x)=10/17. I an not sure how to solve the Tan(x) part. Am I supposed to do Tan-1(x)? Could someone help please?? Thanks!
  75. Calculus

    Below are the 5 problems which I had trouble in. I can't seem to get the answer in the back of the book. Thanks for the help! lim (theta-pi/2)sec(theta) theta->pi/2 Answer: -1 I am not sure what to do here. lim (tan(theta))^(theta) theta->0+ Answer:1
  76. Geometry

    Please check for me .Thanks A building cast a shadow 23 feet long when the angle of the sun is 52 degree. Find the height of the building to the nearest integer. Let X be the height of the building Tan 52 degree =x/23 23 tan 56 =294feet x = 23 tan 52 =
  77. calculus

    what is the integral of {sin(x)tan(x)} i tried turning tan(x) into sin(x)/cos(x) then doing u substitutions but i always have an extra sin(x) left. can you help me pleeeease
  78. math (trigonometry)

    A=170 degree then prove that Tan A/2=-1-rot(1+Tan^2 A)/Tan A
  79. pre-calc help !!!!!!!

    1)tan^2x=3 ? 2)tan x sin^2x=tan x ? 3)2cosx sinx - cos x=0
  80. Math(Please help)

    1)tan 5 degrees + tan 25 degrees / 1 tan 5 degrees tan 25 degrees = sqrt 3 / 3 Am I correct? 2) Complete the identity tan^2Q - 3sinQtanQsecQ = -2tan^2Q Correct?
  81. Math(Please help)

    1)tan 5 degrees + tan 25 degrees / 1 tan 5 degrees tan 25 degrees = sqrt 3 / 3 Am I correct? 2) Complete the identity tan^2Q - 3sinQtanQsecQ = -2tan^2Q Correct?
  82. Math

    Determine each tangent ratio to four decimal places using a calculator. A) tan 74 degrees B) tan 45 degrees C) tan 60 degrees D) tan 89 degrees How do I figure this out !?
  83. Precalculus

    The directions are write the expression as the sine, coine, or tangent of an angle. (tan 25 degrees + tan 10 degrees) / [1 - [(tan 25 degrees)(tan 10 degrees)]]
  84. calculus

    Find Indefinite Integral of dx/(x(x^4+1)). I think that Im complicating it too much. I moved the dx out making it 1/(x(x^4+1))dx than 1/(x^5+x)dx. I think i have to use formula indef integral of dx/(x^2+a^2) = 1/a(tan^-1(x/a)) but im stuck i don't know
  85. Pre Cal.

    Evaluate tan(cos^(-1)(ã3/2 )+tan^(-1)(ã3/3))? arccos(sqrt(3) / 2) = pi / 6 arctan(sqrt(3) / 3) = pi / 6 tan(pi / 6 + pi / 6) = tan(pi / 3) = sqrt(3).
  86. Calculus 12th grade (double check my work please)

    2- given the curve is described by the equation r=3cos ¥è, find the angle that the tangent line makes with the radius vector when ¥è=120¨¬. A. 30¨¬ B. 45¨¬ C. 60¨¬ D. 90¨¬ not sure A or D 2.) which of the following represents dy/dx when
  87. trig

    Given that tan 45=1, use tan(x+y) to show that tan 22.5= /2 - 1. (/is square root sign
  88. trigonometry (please double check this)

    Solve the following trig equations. give all the positive values of the angle between 0 degrees and 360 degrees that will satisfy each. give any approximate value to the nearest minute only. a.) ( I got confused doing this 1 can you help me with it.) 3 sin
  89. physics (speed of plane by radar)

    The radar stations A and B, separated by the distance a = 500 m, track the plane C by recording the angles α and β at 1-second intervals, If three successive readings are shown in the table,calculate the speed v of the plane and the climb angle y
  90. Math

    Could someone explain the steps for this question. Simplify the expression tan(5pi/8)-tan(3pi/8)/1+tan(5pi/8)tan(3pi/8)
  91. Calculus - Question

    Am I allowed to do this? for the integral of ∫ sec^4 (3x)/ tan^3 (3x) dx I change it to ∫ sec^4 (3x) tan^-3 (3x) From here I use the rule for trigonometry functions.
  92. math

    Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of si -pi/6, cos 5/3pi and tan 4pi/3. I have found the answers to the first three using the special tables
  93. Math-Limits

    sqrt(1+tan x)-sqrt(1+sin x) lim all divided by x^3 x-->0 Use that Sqrt[1+x] = 1+ 1/2 x + 1/2 (-1/2)/2 x^2 + 1/2(-1/2)(-3/2)/6 x^3 + O(x^4) You can thus write the numerator as: 1/2 [tan(x) - sin(x)] - 1/8 [tan^2(x) - sin^2(x)] + 1/16 [tan^3(x) -
  94. maths

    Derivative of √ tan x is, Answer: A. sin 2 x/ √ tan x B. cos 2 x/ 2 √ tan x C. sec 2 x D. None of these
  95. Trigonometry

    Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'' g. tan
  96. Trig

    Use the fundamental identities to simplify the expression: cot beta sec beta I used 1+tan^2u=secu since cot is the inverse of tan. I flipped the tangent, then so it was 1+ (1/tan). But the book's answer is the cosecant of beta. Where did this come from??
  97. calculus

    Let F(x)= the integral from 0 to 2x of tan(t^2) dt. Use your calculator to find F″(1) By applying the fundamental theorem of calculus, I got the derivative of the integral (F'(x)) to be 2tan(2x^2) When I take the derivative to find F''(x) I get 8x
  98. Trig Identities

    Proving identities: 1) 1+ 1/tan^2x = 1/sin^2x 2) 2sin^2 x-1 = sin^2x - cos^2x 3) 1/cosx - cosx = sin x tan x 4) sin x + tan x =tan x (1+cos x) 5) 1/1-sin^2x= 1+tan^2 x How in the world do I prove this...please help... I appreciateyour time thankyou soo
  99. Pre Calculus

    I keep trying to solve this by factring but I can't seem to get! It's so frustrating! The problem is 1+tan2x=0 This is how I worked the problem before: 1+((2tanx)/(1-tan^2x))=0 ((2tanx)/(1-tan^2x))= -1 Then I cross multiplied to get: -1 + tan^2x = 2 tanx
  100. Calculus : Derivative

    If tan^-1(x^2-y^2/x^2+y^2) = a, prove that dy/dx = x(1 - tan a)/y(1 + tan a) Please solve!!!